A nuclear medicine diagnosis apparatus using a Compton camera has been garnering attention recently because it has a variety of advantages compared to the other nuclear medicine diagnosis apparatuses.
A Compton camera is basically configured by combination of a former-stage detector and a latter-stage detector. A former-stage detector causes an incoming gamma ray (photon) from an object Compton scattering (hereinafter sometimes referred to as a reaction) which generates a recoil electron and a scattered gamma ray. The generated recoil electron is detected by the former-stage detector and the generated scattered gamma ray is detected by the latter-stage.
Since the energy and direction of the incoming gamma ray can be uniquely determined by the detected information, the spatial distribution of the gamma ray source can be imaged by the image reconstruction technique.
The detail of the Compton camera is disclosed in Patent Document 1 below. In the case of acquiring a diagnostic image of an object using such Compton camera, the images are usually constructed using so-called Compton camera reconstruction algorithm wherein the detection result of gamma rays using the Compton scattering is taken into consideration.    Patent Document 1: JP-A-S63-158490